Or intracranial EEG (iEEG), is the practice of using electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex. ECoG may be performed either in the operating room during surgery (intraoperative ECoG) or outside of surgery (extraoperative ECoG). Because a craniotomy is required to implant the electrode grid, ECoG is an invasive procedure.
The signals recorded by ECOG and Stereoelectroencephalography (SEEG) have very similar spectral power and phase-amplitude coupling, suggesting that both modalities are comparable from an electrodiagnostic standpoint in delineation of the epileptogenic network 1).
see Cortical stimulation.
The detectability of high frequency oscillations (HFO, >200Hz) in the intraoperative ECoG is restricted by their low signal-to-noise ratio (SNR).
Low-noise amplification improves the detection of the evoked high frequency oscillations (HFO, >200Hz) in recordings with subdural electrodes with low impedance 2).